Circuit closer



May 12, 1931. c. w. JOHNSON 1,804,622

CIRCUIT CLOSER Filed April 25, 1928 n MZZTZZ/(lflhlfail,

Patented May 12, 1931 UNITED STATES PATENT OFFICE CHESTER W. JOHNSON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE A. L. SMITH I IRON WORKS, OF CHELSEA, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS CIRCUIT CLOSER Application filed April 25,

This invention relates to an electric circuit closer or switch particularly intended and adapted for the uses indicated in my prior Patent No. 1,659,712, granted December 18, 1928; that is, to be mounted upon the steering wheel of an automobile in circuit with a signal light, or equivalent electrically operated indicating signal, for closing the circuit automaticall when the wheel is turned, or manually wit out turning the Wheel. The main object of the invention, is to provide a circuit closer of the character and for the purposes of that shown in the 7 said patent, having improvements of construction by which its manufacture is simplified and its cost reduced; to the end that switches may be made in quantities at minimum cost and furnished to users at a low price. Other objects appear in connection with the following description of the preferred embodiment of the invention, from which also appear the new steps and characteristics which constitute the present invention.

In the drawings,

Fig. 1 is a central sectional View of an improved switch embodying this invention;

Fig. 2 is a cross section of the switch on the line 2-2 of Fig. 1;

Fig. 3 is a plan view showing the steering wheel of an automobile having two switches of this character applied thereto for respectively controlling right and left direction signals;

Fig. 4 is a detail sectional View showing the position of the mobile circuit closing body of the switch in closing the circuit.

Like reference characters designate the same parts wherever they occur in all the figures.

The operative parts of the switch are carried by a body or base 1 made of insulating material, preferably a plastic material which can be moulded, such as bakelite, hard rub-- ber composition, etc. Preferably also the base is of cylindrical form externally in order that it ma be mounted in a surrounding holder or c ip 2 and readily adjusted angularly through small amounts by rotation in the holder. The holder or clip here 1928. Serial No. 272,678.

shown is a metal band which surrounds the base in a rabbeted portion thereof which is bounded by a shoulder 3. The ends of this band aproach one another and carry lugs 4.

through which passes a screw 5 uniting the band to a jaw 6, forming one member of a clamp. The other member of the clamp is a complemental jaw 7 of angular form tied to the jaw 6 by a connecting take up screw 8 and having a lug 9 throu h which an abutment or stop screw 10 is adjustably threaded- By this means the holder may be secured to the spoke of an automobile steering wheel, or other support. The holding band of the base at the inner end of the cavity and at opposite sides of the axis of the base. A smaller extension cavity projects inward from the end of the cavity 12, between the binding screws 13 and 14 and preferably in the axis of the base. Leading from the extension cavity 15 to the opposite side of the base is a central passage or hole in which a tubular rivet, forming a bushing 16 is located, said rivet having a flange or head on one end within the cavity 15 and extending at its other end from the op posite face of the base.

The said opposite face of the base is formed with a shallow recess within its rim 17 and with a deeper groove 18 mainly concentric with the axis of the base and almost, but not wholly, surrounding such axis, its ends being closed and separated from one another by a dam 19 formed of the material of the base, as shown in Fig. 2. A cover 20 is fitted in the recess within the lip 17 of the base and overlaps the groove 18, making close contact with the opposite edges of such groove and thereby closing it. This cover has a central hole which receives the protruding end of the bushing 16, which is headed; over to secure the cover in place. 1 a

At the opposite side of the axis from the dam 19, and at opposite sides of a plane.

through the axis and said darn, the groove diverges from its concentric formation, providing eccentric passages 21 and 22, the Wallsof which at one side form shoulders 23 and 2a embracing a cup or well 25, and on the other side form a projection 26 centrally located with respect to the cup and projecting well toward, or partially into the entrance of such cup. In this cup is placed a mobile conducting body 27, preferably a quantity of mercury sufficient to substantially fill the cup and touch, or embrace more or less, the projection 26. The latter, cooperating with the shoulders 23 and 24:, tends to retain the mercury in the cup and prevents it from running out when the switch is turned about its until it has been thus turned to a prescribed minimum degree.

In one arm of the groove 17 is placed a rod'or wire 28 of conductive material, preferably iron or steel, which is inert to the amalgamating power of mercury. Said rod is curved conforinably to the arm. of the groove in which it is located, and is placed so that it is separated at all points from the cover. Its ends are passed through holes leading from the bottom of the groove into the opposite cavity 12. One end is bent back against the end wall of the cavity, while its other end 29 leads and is clamped to the binding screw 13. It may be so placed ineither arm; and whether placed in the right hand or lefthand arm depends on whether the switch is to be used for closing the circuit when rotated in the right hand or the lefthand direction. In the case shown in Figs. Land 2, the switch closes the circuit by lefthand rotation, wherefore the conductive bar 28 is placed in the lefthand arm of the groove. Conductors 30 and 31 are connected to the binding screws 13 and 14:, respectively. These conductors are placed in circuit with thesignal device and a source of current'in a manner well understood by electricians, and therefore not necessary to be described herein. The conductor 31 is connected electrically by a conductor 32 with the bushing 16, which is of metal and therefore electrically conductive, and through the latter with the cover plate 20, which also is of metal and electrically conductive. Hence the gap at the switch to be closed by the-mobile body 27 is that between the cover 20 and the plate 28, and this gap is filled andthe circuit closed whenever the switch is rotated far enough to cause the mobile body to flow or run 'by gravity into that part of y the groove which is occupied by plate 28.

Also connected to the binding screws 13 and 14 are contact members 33 and 3a which extend toward one another partly across the cavity or chamber 15, but are separated I from one another. .A plunger 35 is mounted to slide endwisein the bushing 16 and carries'on its protruding threaded end a head or button 37 of insulating material. On its inner endit carries an integral head 33, or at least a knob, made of conductive material, adapted to engage both Contact inembers33 and 3%, when the button 37 is pressed inwa' A spring confined between the cover 20 and abutment 37 normally holds the latter out to the limit permitted by the knob 38, thereby holding the latter separated from the contacts 33 and 34. This spring is preferably made as a spider havir a'central hole, which receives a boss lOon the inside of the knob, and three or more curved or bent resilient legs bearing at their free ends on the cover. 3

The switch above described lents itself particularly well to the purposes of a direction sigi'ial for motor vehicles in connection with visible signals designed to show when the vehicle is about to be turned to right or left. For this purpose two such switches are mounted on the steering wheelfof the car in electrical connection withthe source of electricity and with the right and left indicating signals, respectively; one at the left, and the other at the right of the post on which thewheel is supported. Fig. 3 shows the switches so mounted on the spokes 4:1 an Q2 of a steering wheel 43, these spokes being in line crosswise of the car when the wheel is in centralposition. They maybe mounted on the rim, or otherwise, as desired, howeventhe clamp device previously described affording a means by which they may be readily secured in any desired position. They are properly adjusted in their into the lowerarm or branchof the passageway. In turning to the right, the mercury runs into the right hand branch of each switch, closing the circuit inthe right hand switch and causing the'signal which india change of direction to the right to be operated. Reverse effect occurs when the wheel is turned to the left. If, in making a sharp turn, the wheelisturned through a complete revolution or more, the mercury runs back toward the pocket, but before d'oing so, it remains inthe closed end of the slot until the wheel has been turned so far that, when the mercury runs back it will be caught in the pocket and will not fall into the other branch of the slot.

In case the driver desires to signal his intention of changing direction before actually reaching the turning point in the road, he may close the appropriate switch by pressing down the button 37 thereof.

What I claim and desire to secure by Letters Patent is:

1. A switch as and for the purpose de scribed, comprising a base of insulating material having a groove in one face, a cover overlying and closing said groove and formed of conductive material, a conductor located in said groove separated from the cover, and means for connecting the conductors of an electric circuit in connection, respectively, with said cover and said conductor.

2. A switch as and for the purpose set forth, comprising a base of insulating material, binding posts mounted in the base, a groove formed in one face of the base extending through nearly a complete circuit about a central point with closed ends near to one another, and having non-concentric portions at the opposite side of the central point from the closed ends forming a mercury pocket, and a projection extending toward the same, a strip of conducting material located in the bottom of one of the branches of said groove, a cover of conducting material secured to the'base overlying and covering said groove, and conductors electrically connecting said conducting strip and cover, respectively, to the before named binding posts.

3. A switch of the character described, comprising a body of insulating material having a central passageway, a bushing of conductive material located in said passage- Way, a groove in one face substantiall concentric with said bushing having close ends adjacent to one another at one side of the center, and a mercury pocket at the other side thereof, a cover of conductive material secured to said bushing to overlie and close said groove, and conductors of an electric circuit connected, respectively, to said bushing and to a conductor in one of the branches of the groove.

4. A switch of the character described comprising a cylindrical body having a recess in one end, a central passageway leading from said recess to the opposite end, and a groove in the face at the latter end substantially concentric with and surrounding said passageway, having adjacent closed ends at one side of the axis and a mercury pocket at the opposite side thereof, a quantity of mercury adapted to occupy said pocket and to run in said groove when the switch is turned about its axis in an inclined plane, binding posts mounted on the base within said chamber at opposite sides of the passage, a bar of conducting material fitted in one of the branches of said groove, a conductor leading from said bar to one of the binding posts, a bushing fitted in said passageway, a conductor leading from said bushing to the other of said binding posts, a cover of conducting material overlying and closing the groove and secured to and by the said bushing, a plunger mounted and movable endwise in said bushing having a bridging conductor on its inner end, a push button secured to the protruding outer end of the plunger, a spring confined 'and reacting between said cover and push button, and contact members secured to the respective binding posts projecting toward one another into position to be simultaneously engaged by the bridging conductor when the push button is pressed upon.

In testimony whereof I have affixed my signature.

CHESTER W. JOHNSON. 

